The Harry Potter series has one huge asset that it has yet to leverage to its fullest: its world. People have seen quite a bit of Hogwarts and Diagon Alley with the original films, and it's true the Fantastic Beasts series has shown them other elements of the wizarding world as well. These stories are fine, but seem more focused at times with adding additional lore and exposition to the viewer's pre-existing knowledge of the original films than anything else, especially in their focus on a younger Dumbledore and Grindelwald.
World-building is great and all, but the true power of the original saga following Harry and friends was so strong and made such an impression because of its characters. Harry is a good friend and is resourceful. Ron is funny and loyal. Hermione is intelligent and headstrong. Their interactions and the way their personalities clash together at times are what people remember the most in the series and make Harry's adventures far more interesting than they would be if they only focused on him discovering magic alone. For the next go that Hollywood takes at the Harry Potter universe, they should focus on the Quidditch World Cup. There are a number of reasons that such a setting would provide for a fascinating film.
A Quidditch Movie Could Take Inspiration From Sports Film Greats
Much like The Mandalorian on Disney+ uses the framework of Western and Samurai movies as a basis for its structure and tone, a Quidditch movie could utilize the successes of past sports films. Movies like Victory, Rudy, Rocky, and more come to mind. A Quidditch movie shouldn't just be a Harry Potter movie, but also a great sports movie in itself. It also has the added benefit of being far more visually interesting than any sport that exists in the world. Sure, audiences have seen Harry play Quidditch, but only briefly and typically there's other plot elements that are the true focus of these scenes, such as in The Sorcerer's Stone when Hermione believes Snape is sabotaging Harry to fall off of his broom.
Additionally, we've never seen a complete tournament on the scale of the World Cup. Just like the real world, The World Cup is a huge deal that gets everybody involved and ready to represent their homeland. Harry Potter's teams still use the same region designations like Australia, Bulgaria, England, France, Germany, Japan, Scandinavia, Spain, and the United States. Making the rivalry between these teams the focus and including plenty of characters with huge egos and ulterior motives could make for a very interesting movie.
Quidditch and Gambling Could Reveal the Seedier Side of Harry Potter
Not to say that the Harry Potter series needs any darkening (it's already quite dark at times), but it could do with a bit of a grungier storyline. Fans of the movies know that the wizarding world has the Death Eaters, which are closest to representing an evil cult or a fascist regime. However, including an evil presence or antagonist could have a more personal feel if it were something like the magic equivalent of the mafia.
Focusing on a character who is, for example, in debt to the magical mafia could help to provide a highly different feel for the movie while also making for a more terrifying, raw villain. Unlike Voldemort, who really doesn't show up in a true capacity until the end of The Goblet of Fire, this villain should be hovering nearby at all times, ready to collect in the event the hero loses their bets. With this angle not only could the movie incorporate more suspense and thriller elements (i.e. giving the slip to enforcers within Diagon Alley) but it would also add much more weight and personal stakes to the outcome of each Quidditch match.
A World Cup Would Make For a More Interesting Clash of Cultures
If there's one gripe to be had with the movie Harry Potter and The Goblet of Fire, it's that the movie introduces a bunch of characters like Viktor Krum and Fleur Delacour that come from entirely different countries and schools, yet fans learn almost nothing about them. Sure, it's nice that Hagrid gets a girlfriend for a movie, but when it comes to characters like Viktor, we get barely so much a crumb of information. This would be easy to correct and account for within a Quidditch World Cup movie because World Cups are inherently a massive crossroads of cultures.
Aspects like a different country's musical styles, their customs, and their past rivalries could come into play. It would be interesting as well to see how the Quidditch crowds differ from Soccer fans, do they also throw their empty bottles of butter beer at the field when they get rowdy? Additionally, much like sports teams take the time to sing their country's songs before they play, it would be dazzling to see if they do anything magical along the same lines. Like a fireworks display, but with wands. There are so many possibilities, it's definitely time for Hollywood to make the Golden Snitch switch.